I had my SSL setup fitted by Williams - as it was the first Aero S5 with SSL suspension I spent some time with Peter Ballard describing the handling I had with the factory setup, and how I wanted the car to feel.
He then set the car up that way (& changed the ARBs too)
We've since adjusted the setup - in my case to raise the ride height and very slightly soften the ride. There's a temptation to make changes regularly in search of the perfect setup. For me, living in the centre of a city that's littered with sleeping policemen I suspect I'll always have a compromise between safely clearing the policemen and optimal ride/handling on the open road. With my current setup I don't hit sleeping policemen, and fully laden I get some float at higher speeds on A roads. Which works for me.
I'd guess any supplying dealer can take you through the same process.
